This invention relates to a printing apparatus using a magnetic image recording process. More specifically, the present invention relates to a printing apparatus which has a recording master formed of magnetic material.
It is known to use a copying machine and an engraving printing apparatus for printing images. Preparations for copying with an electronic copying machine are easy to make, and the copying machine is easy to use. In the engraving printing apparatus, a form is made from a manuscript page and the manuscript can be repeatedly copied on recording paper using the form. The engraving printing apparatus makes high-speed printing possible after the form has been made. Use of engraving printing apparatus has an advantage in that copying costs less with increasing numbers of copies. The apparatus, however, requires a lot of time and labor to prepare for printing work, because of the process of making the form. The electronic copying machine prints at a much lower speed than conventional gravity printing machines. The electronic copying machine must go through numerous processes, such as electrostatic charging, exposure, developing, and electro-removal for each individual copy of a manuscript. When the copying machine copies at a higher speed, over-speed developing may deteriorate the printed image.
Therefore, an apparatus has been practically used which can copy at the same speed as an engraving printing machine, yet does not require the same operations or preparations as a printing machine. An example of this apparatus is the printing apparatus disclosed in the U.S. Pat. No. 4,072,957. The printing apparatus comprises a print drum with a magnetic thin film and a magnetic head to record magnetic latent images on the print drum. The printing apparatus makes magnetic toner adhere to the magnetic latent images to develop the images. Then the apparatus transfers and prints the images developed with magnetic toner onto a paper. After the apparatus forms magnetic latent images on the print drum, it prints by repeated developing with magnetic toner. The printing apparatus scans the print drum from one end to the other by the recipiocating movement of a magnetic head, to form magnetic latent images. Therefore, the printing apparatus takes time to form magnetic latent images.